Mercury boiler



Oct. 18, 1932. 3, 55551-5 1,883,635

MERCURY BOILER Filed May 17, 1929 2 Sheets-Sheet 1 Fig! INVENTOR 6 M wfflbRNEg' G. D. EBBETS MERCURY BOILER Oct. 18, 1932.

2 Sheets-Sheet 2 Filed May 17. 1929 w wk m hm Patented a. 18, 1932UNITED STATES,

PATENT OFFICE GEORGE D. EBIBETS, OF KENILWOBTH, NEWJERSEY, ASSIGNOR TOTHE BABCO GK & WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OFNEW JERSEY IERC RY BOILER Application filed Kay 17, 1929. Serial No.863,872.

This invention relates to a mercury boiler so arranged that the mercuryvapors can be recovered in case of rupture of a mercury Vapor generatingelement.

The invention will be understood from the description in connection withthe accompanying drawings in which Fig. 1 is a vertical section throughanillustrative embodi- 'ment of the invention; Fig. 2 is a verticalsection on an enlarged scale, showing some of the details; Fig. 3 is aside View of amodification of some of the parts; and Fig. 4 is a sectionat right angles to Fig. 3.

In the drawings reference character 1 inv dicates the walls of thefurnace in the upper portion of which a mercury boiler is located havingmercury vapor generating tubes 2 depending from headers 3 in the wellknown way. Feed ipes 4 for mercury are provided leading to t e upperportions of the drums 3 and mercury vapor pipes 5 extend from the upperportions of the drums 3 to a header 6 from which tubes 7 lead to aheader 8'that may be connected to the place where the mercury vapors areused.

An economizer 9 of a well known sort may be located in the flue 10through which the waste gases from the furnace pass down wardly. An airheater 11 is also located in the flue 10, preferably below theeconomizer 9. A receptacle 13 through which the waste gases pass isprovided below the air heater 11. A series of perforated pipes 14 extendacross the upper portion of the receptacle 13 for spraying water intothe receptacle 13,

which is provided with a sloping. bottom. A

water outlet pipe 15 extends from a point along the sloping bottom ofthe receptacle some distance above its lowermost point. A

sump 16 is provided at the lowest point of the sloping bottom of thereceptacle 13 and a U-shaped outlet 17 leads from the sump 16 to acontainer 18 at the lower portion of which an outlet pipe 19 isprovided. The

' outlet end of the U-shaped pipe 17 extends upwardly into the container18 to a level approximately the same as the bottom of. the sump 16. Thepipe 17 serves as a trap for mercury.

Heretofore when mercury boilers have become ruptured the mercury vaporsbecame out through the stack and lost. By the present invention themercury, which would otherwise be lost in this way, is recovered. Thehot gases carrying the mercury vapors, which accidentally escape. intothese gases, are cooled by passing across the tubes of the economizer 9and are further cooled by passmg through the air heater 11. l/Vhen a rupture occurs to cause mercury vapors to'es cape into 'the hot gases, thepipe leading to the perforated pipes 14 is opened to cause sprays to beprojected downwardly into the gases passing through the receptacle 13,thus further cooling the gases and condensing the mercury vapors andremoving the mercury from the gases. The spray may be operated manuallywhen a rupture occurs or it may be made to operate automatically when achanged condition occurs in the boiler due to rupture, such as adecrease in the pressure in the boiler or an increase in the temperatureof the escaping furnace gases. The mixture of water and mercury collectsin the lower portion of the receptacle 13, the mercury gravitating tothe bottom. lVhen the mercury accumulates sulficiently to fill the tube17 with a slight excess, the excess mercury passes into the container 18and out through the pipe 19'. The excess water escapes through the pipe15 as soon as the water level reaches this point. The mercury in thetube 17 prevents water from passingout through this tube. The legs ofthe U-tube are sulficiently long to enable enough water to accumulate inthe receptacle 13 to overflow through the pipe 15, without forcing thelevel of the mercury to the lower'end ofthe leg that is attached to thesump 16.

The economizer 9 may be used'for heating water that passes through it orit may be used for preheating the mercury before it is introduced intothe drums 3 during the normal operation of the boiler. The air heater 11may heat combustion air for the boiler furnace.

In Figs. 3 and 4 a modification is shown in which the mercury and waterare separated after the mercury has been condensed by the water spray,and the mercury is withdrawn automatically from the receptacle after apredetermined amount thereof has accumulated. In this modification thebottom portion of the receptacle 13 is made separate from the remainderof the receptacle and is movable in a vertical direction. A liquid seal21 is provided between the upper edge 22 of the portion 20 and the loweredge 23 of the receptacle 13. Supports 24 are provided near the lowerportion of the receptacle 13 and supporting rods 25 for the lowerportion 20 are supported upon springs 26 upon the supports 24. The rods25 are attached to brackets 27 upon the movable portion 20.

A valve seat 28 is provided in the lower end of the conical bottom ofthe portion 20 and a fixed valve 29 is provided for the valve seat 28.The stem 30 of the valve 29 is screwed into a threaded lug in the fixedout- 1 let pipe 31-and an expansible tube connection 32 is providedbetween the valve seat 28 and the upper end of the pipe 31. The pipe 31may be supported in a fixed position by means of the support 33.

In the modification shown in Figs. 3 and 4 the valve 29 is kept closednormally by the springs 26 holding the bottom 20 in its uppermostposition with the seat 28 and valve 29 in contact. The springs are soadjusted that the weight of a suflicient amount of water accumulated inthe portion 20 to overflow through the outlet 15 will not compress thesprings 26 sufficiently to move the portion 20 downwardly. If, however,a portion of the liquid in the bottom 20 filling the same to theoverflow pipe 15 is mercury, the weight will be suflicient to open thevalve 29 and permit the mercury to escape. As soon as the mercuryescapes the springs 26 raise the bottom with its decreased weight ofliquid sufficiently to close the valve 29 before the water begins toescape. The mercury and water are thereby automatically separated fromeach other. The mercury that would otherwise be wasted is recovered.

A soot blower 34 shown somewhat diagrammatically in Fig. 1 may beprovided in the receptacle 13 to remove soot that may collect during thenormal operation vof the boiler.

I claim:

1. lln a mercury boiler, a flue for spent gases leaving said boiler andmeans in said flue for recovering mercury from said gases that mayescape from said boiler into said gases, said means comprising a coldwater spray, and over-flow means actuated by a predetermined bulk ofmercury within said recovering means.

2. The combination in a mercury boiler of an outlet for the heatinggases, a mercury condensing chamber associated with said outlet andthrough which said gases pass, means for cooling said gases in saidchamber to condense mercury vapor mixed with said gases and to depositliquid mercury in the bottom thereof, an outlet in the bottom of saidchamber and means operated by the accumulation of mercury for deliveringmercury only through said outlet.

3. The combination in a mercury boiler of an outlet for the heatinggases, a mercury condensing chamber associated with said outlet andthrough which said gases pass, means for cooling said gases in saidchamber to condense mercury vapor mixed with said gases and to depositliquid mercury in the bottom thereof, an outlet in the bottom of saidchamber and valve means operated by the accumulation of mercury fordelivering mercury only through said outlet.

GEORGE D. EBBETS.

